The present disclosure relates to a speaker unit. More particularly, the present disclosure relates to a speaker unit in which irregularity portions having different forms are formed in plural leg portions of a frame at least in one-to-one correspondence to reduce resonance, thereby enhancing a sound quality without causing reduction of the strength of the frame.
Some speaker units are of a type in which a vibrating plate is vibrated by a driving force of a magnetic circuit having a magnet and a coil. In such a type of speaker unit, edges of the vibrating plates and the magnetic circuits are mounted to portions of the frame.
The frame includes a circuit mounting portion, an edge mounting portion, and plural leg portions. In this case, the magnetic circuit is mounted to the circuit mounting portion, and an edge of the vibrating plate is mounted to the edge mounting portion. Also, the circuit mounting portion and the edge mounting portion are coupled to each other through the plural leg portions which are provided in spaced relation to one another in a circumferential direction.
In the speaker unit as described above, the vibrating plate is vibrated, thereby outputting a sound. However, in the case where the frame is vibrated by a reaction following the vibration of the vibrating plate and also the plural leg portions are formed in the same size and the same shape, it is feared that a resonance sound is generated at a specific frequency to reduce the sound quality.
In order to cope with such a situation, some existing speaker units are constructed in such a way that the strengths of plural leg portions are made non-uniform, thereby preventing the reduction of the sound quality. This sort of speaker unit, for example, is described in Japanese Patent Laid-Open No. Hei 7-95687.
However, when the strengths of the plural leg portions are made non-uniform, there is the possibility that the strength as a whole of the frame is reduced. In particular, in a use application in which the speaker unit is used in an environment causing the vibration to be readily generated as with an on-vehicle speaker unit, there is the possibility that the strength is insufficient.
On the other hand, others are constructed in such a way that reinforcing ribs provided in leg portions of the frame, thereby increasing the strength. This sort of speaker unit, for example, is described in Japanese Utility Model Laid-Open No. Hei 5-18198.
However, in the speaker unit described in Japanese Utility Model Laid-Open No. Hei 5-18198, it is possible to increase the strength. However, since the leg portions are formed in the same shape and the same size, including the reinforcing ribs, it is feared that the resonance sound is generated at the specific frequency, thereby reducing the sound quality.
The present disclosure has been made in order to solve the problems described above, and it is therefore desirable to provide a speaker unit in which a sound quality can be enhanced without causing reduction of the strength of a frame.
In order to attain the desire described above, according to an embodiment of the present disclosure, there is provided a speaker unit including: a magnetic circuit having a magnet and a coil; a vibrating plate adapted to be vibrated by a drive force of the magnetic circuit; and a frame having a circuit mounting portion to which the magnetic circuit is mounted, an edge mounting portion to which an edge of the vibrating plate is mounted, and plural leg portions through which the circuit mounting portion and the edge mounting portion are coupled to each other and which are provided in spaced relation to one another in a circumferential direction, in which irregularity portions are provided in said plural leg portions, respectively, and forms of the irregularity portions are made different from each other at least in two of said leg portions.
Therefore, in the speaker unit described above, the resonance frequency is dispersed in the leg portions of the frame.
Secondly, preferably, in the speaker unit described above, of the forms of the irregularity portions, sizes may be made different from each other.
Of the forms of the irregularity portions, the sizes are made different from each other, whereby the degree of freedom for a design of the frame is increased.
Thirdly, preferably, in the speaker unit described above, of the forms of the irregularity portions, shapes may be made different from each other.
Of the forms of the irregularity portions, the shapes are made different from each other, whereby the degree of freedom for a design of the frame is increased.
Fourthly, preferably, in the speaker unit described above, of the forms of the irregularity portions, numbers may be made different from each other.
Of the forms of the irregularity portions, the numbers are made different from each other, whereby the degree of freedom for a design of the frame is increased.
Fifthly, preferably, in the speaker unit described above, the leg portions may be provided by four; of the four leg portions, each two leg portions may be provided so as to be located in opposing corners, respectively; the numbers of irregularity portions formed in each two leg portions located in the opposing corners, respectively, may be made equal to each other; and the numbers of irregularity portions formed in each two leg portions adjacent to each other in a circumferential direction may be made different from each other.
Of the four leg portions, of the four leg portions, each two leg portions are provided so as to be located in opposing corners, respectively; the numbers of irregularity portions formed in each two leg portions located in the opposing corners, respectively, are made equal to each other; and the numbers of irregularity portions formed in each two leg portions adjacent to each other in a circumferential direction are different from each other, whereby with the simple construction, the resonance frequency in the leg portions of the frame is dispersed.
Sixthly, preferably, in the speaker unit described above, the leg portions may be provided by four; of the four leg portions, each two leg portions may be provided so as to be located in opposing corners, respectively; and sizes of the irregularity portions formed in each two leg portions in the opposing corners may be made different from each other.
Of the four leg portions, each two leg portions are provided so as to be located in opposing corners, respectively; and sizes of the irregularity portions formed in each two leg portions in the opposing corners are made different from each other, whereby with the simple construction, the resonance frequency in the leg portions of the frame is dispersed.
Seventhly, preferably, in the speaker unit described above, parts of the leg portions may be punched out in a thickness direction, thereby forming the irregularity portions integrally with the leg portions.
The parts of the leg portions are punched out in the thickness direction, thereby forming the irregularity portions integrally with the leg portions, whereby the irregularity portions are readily formed.
According to the embodiment of the present disclosure, firstly, the speaker unit includes: the magnetic circuit having the magnet and the coil; the vibrating plate adapted to be vibrated by the drive force of the magnetic circuit; and the frame having the circuit mounting portion to which the magnetic circuit is mounted, the edge mounting portion to which the edge of the vibrating plate is mounted, and the plural leg portions through which the circuit mounting portion and the edge mounting portion are coupled to each other and which are provided in the spaced relation to one another in a circumferential direction, in which the irregularity portions are provided in the plural leg portions, respectively, and the forms of the irregularity portions are made different from each other at least in two of the leg portions.
Therefore, the peak of the resonance is dispersed and thus the sound quality can be enhanced without reducing the strength of the frame.
Secondly, of the forms of the irregularity portions, the sizes are made different from each other.
Therefore, after the degree of freedom for the design of the frame has been increased, the sound quality can be enhanced.
Thirdly, of the forms of the irregularity portions, the shapes are made different from each other.
Therefore, after the degree of freedom for the design of the frame has been increased, the sound quality can be enhanced.
Fourthly, of the forms of the irregularity portions, the numbers are made different from each other.
Therefore, after the degree of freedom for the design of the frame has been increased, the sound quality can be enhanced.
Fifthly, the leg portions are provided by four; of the four leg portions, each two leg portions are provided so as to be located in the opposing corners, respectively; the numbers of irregularity portions formed in each two leg portions located in the opposing corners, respectively, are made equal to each other; and the numbers of the irregularity portions formed in each two leg portions adjacent to each other in the circumferential direction are be different from each other.
Therefore, with the simple construction, the sound quality can be enhanced.
Sixthly, the leg portions are provided by four; of the four leg portions, each two leg portions are provided so as to be located in opposing corners, respectively; and the sizes of the irregularity portions formed in each two leg portions in the opposing corners are made different from each other.
Therefore, with the simple construction, the sound quality can be enhanced.
Seventhly, the parts of the leg portions are punched out in the thickness direction, thereby forming the irregularity portions integrally with the leg portions.
Therefore, the irregularity portions can be readily formed, and the strengths of the legs can be enhanced.